Atmospheric nozzle control



NOV. 18, 1958 c, DERMOND 2,860,616

ATMOSPHERIC NOZZLE CONTROL Filed May 31, 1957 INVENTOR. fizz/{gaze Claw/22am 2 Sheets-Sheet 1 Nov. 18, 1958 c. D ERMoND 2,860,616

ATMOSPHERIC NOZZLE CONTROL Filed May 31, 1957 2 Sheets-Sheet 2 INVENTOR. f/d ,f' fzazzce C/Q'ZWW J a? ATMOSPHERIC N OZZLE CONTROL Lawrence C. Dermond, Rochester,

General Motors Corporation, ration of Delaware Application May 31, 1957, Serial No. 662,928 Claims. .(Cl. 123-119) N. Y. assignor to Detroit, Mich, a corpo- -f'uel flow through the nozzle is not affected by the variations in manifold depression to which the nozzle is subjected.

' -While under normal operating conditions it is desirable thatthe fuel flow-through the nozzle be unaffected by manifold vacuum, it has been found that thisforce may beutilized undercertain operating conditions to provide fuel enrichment. With the engine cold it has been found necessary to provide means for enriching the normal fuelair mixture of a fuel injection system. system noted this is achieved by a temperature responsive In the Dolza mechanismw-hich causes-the mechanical advantage of a fuel control linkage to be changed to insure fuel enrichment for a given time interval.

Inthe present device a simple means has been provided whereby manifold vacuum may act directly on the nozzle fuel stream to thereby facilitate cold running enrichment. "The present device may be used alone or in combination withtheprevious device which achieved fuel enrichment by altering the mechanical advantage of the fuel metering linkage.

In the present device the cold running fuel enrichment is realized by providing an engine temperature responsive valve adapted to cut off the flow or bleed of atmospheric reference air to the fuel nozzle as long as the engine is .cold,and further to'gradually restore the flow of such air as the engine temperature increases.

The details as well as other objects and advantages of the present invention are set forth in the description which follows.

In the drawings:

Figure 1 shows a fuel injection system embodying the present invention;

Figure 2 shows the subject invention in greater detail; and

Figure 3 is a modified form of temperature control device.

The fuel injection system functions in the same manner as in the aforenoted copending application except as will be specifically described herein. In general, the fuel injection system comprises an air intake casing having air induction passage 12 formed therein. A venturi 14 is formed in said induction passage which also includes a throttle valve 16 disposed posteriorly of said venturi. A fuel metering mechanism is shown generally at 18 and is adapted to supply metered quantities of fuel to the individual cylinder fuel supply conduits 20. The quantity of fuel supplied to the fuel conduits 20 is proportional to the mass of air flow through induction passage 12 as described in detail in the aforenoted copending application.

United States Patent 0 Patented Nov. 18, 1958 Each fuel conduit 20 terminates in a nozzle 22 supported upon and partially projecting within the individual cylinder intake passages '24. Each fuel nozzle 22 includes a fuel inlet passage 26 which terminates in a fuel metering orifice 28. The fuel from metering orifice 28 is projected in a stream across the enlarged chamber 30 where it is targeted through a larger orifice 32. The chamber30 is adapted to communicate with a conduit 34 which communicates at its other end with the air intake casing-10 to provide reference air to the nozzle 22. The orifice '32 in the nozzle 22 has no metering effect on the fuel flow throughthe nozzle but does meter the quantity of air which is mixed with the fuel stream prior to its injection into the intake passage 24. As already noted, under normal operating conditions the reference air in chamber 30 neutralizes the manifold vacuum force acting ont-he end of the nozzle 22 and thereby stabilizes the metered fuel flow.

"to the cylinders of the engine passes through the venturi 14 and insures a maximum-metering signal for the fuel metering control device 18.

As best seen in Figure l, a boss 36 is formed onthe intake casing 10to which theair conduit 34 is suitably connected. A rotatable valve member 38 is disposed in boss 36 andis 'adaptedto control thequantity of air flow through conduit 34. As seen in Figure 2, a. lever 40 is fixed to the valve 38 and is articulated through link 42, lever 44 and link 46 to an engine temperature responsive device 48. The temperatureresponsive element 48 may be disposed within the manifold exhaust cross-over passage 50 in order to respond closely to the natural engine temperature, or may be disposed on the air intake casing 10 as shown inFigure 3.

While it is preferable to communicate the air conduit 34 with: the induction passage 12 intermediatethe throttle valve 16 and the venturi14, it is possible to communicate theconduit with the passage at any point anterior to the throttle valve. In other words, it is possible to communicate the air conduit 34 with the air inductionpassage 12 anteriorly of the venturi 14 if desired.

Under normal operating conditions valve 38 will be opened whereby the pressure differential existing between the air induction passage 12 anteriorly of throttle 16 and the cylinder intake passage 24 proximate nozzle 22will cause air to flow or be bled through conduit 24 and nozzle chamber 30. In this way the manifold vacuum acting on the nozzle 22 will be neutralized and have no effect on the quantity of metered fuel flowing through the nozzle. However, with the engine cold the valve 38 will be closed, as shown in Figure 1, cutting off the supply of reference air to the metering nozzle as a result of which the manifold depression acting on the nozzle 22 will cause the flow of fuel through the nozzle to be increased thereby enriching the fuel-air ratio while the engine is cold.

As the engine temperature increases valve 38 will progressively open under the influence of the temperature responsive element 48 permitting the gradual flow or bleed of air through conduit 34. When the engine has reached it normal operating temperature valve 38 will be completely opened under which condition manifold vacuum will no longer have any enrichment effect on the fuel flowing through the nozzle 22.

In either of the modifications of Figures 2; or 3 a fast idle cam 52 or 52' is pivotally mounted on the induction casing 10 and suitably articulated to the temperature responsive element 43 or 4% by a link 46 or 46 in order to control the idle position of the throttle valve 16 in accordance with engine temperature in the Well known manner.

.in said passage for controlling the quantity of air flow therethrough, means for supplying a metered quantity of fuel to the passage posteriorly of said throttle, said means including a nozzle disposed in said passage proximate the individual cylinders of the engine, a conduit communicating said nozzle with said intake passage anteriorly of said throttle, the pressure differential across the throttle normally causing air to flow through said conduit whereby manifold vacuum acting on said nozzle normally has no effect on the quantity of fuel flowing therethrough When the air flow through said conduit is unrestricted, a valve disposed in said air conduit, and engine temperature responsive means connected to said valve for restricting the quantity of air flow through said conduit in inverse proportion to the temperature of said engine.

2. A fuel injection system for an internal combustion engine comprising an air intake passage for supplying air to the individual cylinders of the engine, a throttle valve in said passage for controlling the quantity of air flow therethrough, means for supplying a metered quantity of fuel to the passage posteriorly of said throttle, said means including a nozzle disposed in said passage proximate the individual cylinders of the engine, a conduit communicating said nozzle with the intake passage anteriorly of said throttle whereby manifold vacuum acting on said nozzle normally has no effect on the quantity of fuel flow therethrough when air flow through said conduit is unrestricted, a valve disposed in said air conduit, engine temperature responsive means connected to said valve for restricting the quantity of air flow through said conduit in inverse proportion to the temperature of said engine, and means for controlling the idling position of the throttle valve, said latter means being connected to said temperature responsive means.

3. A fuel injection sytsem for an internal combustion engine comprising an intake casing, an air induction passage formed in said casing for supplying air to the individual cylinders of the engine, a throttle valve in said passage for controlling the quantity of air flow therethrough, means for supplying a metered quantity of fuel to the passage posteriorly of said throttle, said means including a nozzle disposed in said passage proximate the individual cylinders of the engine, a valve disposed in said intake casing and communicating with the induction passage anteriorly of the throttle valve, a conduit communicating said nozzle with said valve whereby the air in said conduit will bleed through said nozzle when the valve is open, and engine temperature responsive means connected to said valve for reducing the quantity of air bled through the nozzle in inverse proportion to the temperature of said engine permitting the manifold vacuum acting on the nozzle to increase the quantity of fuel flow when the engine is cold.

4. A fuel injection system for an internal combustion engine comprising an air intake passage, a venturi formed in said passage, a throttle valve in said passage posteriorly of said venturi for controlling the quantity of air flow therethrough, a plurality of cylinder intake passages communicating with said air intake passage, means for supplying a metered quantity of fuel to each of said cylinder intake passages in accordance with the mass of air flow through said venturi, said means including a nozzle disposed in each of said cylinder intake passages proximate said cylinder, a conduit communicating each nozzle with said intake passage anteriorly of said throttle valve, the pressure differential between the air intake passage and each cylinder intake passage adjacent the nozzle causing air to bleed through the conduit to prevent manifold vacuum from modifying nozzle fuel flow, said air conduit communicating with said air intake passage intermediate said throttle valve and said venturi, a valve disposed in said air conduit, and temperature responsive means for controlling said valve to decrease the quantity of air .bleed through said conduit in inverse proportion to engine temperature whereby manifold vacuum will increase nozzle fuel flow when the engine is cold.

5. A fuel injection system for an internal combustion engine comprising an air intake passage for supplying fuel to the individual cylinders of the engine, a throttle valve in said passage for controlling the quantity of fuel flow therethrough, means for supplying a metered quantity of fuel to the individual cylinders of the engine in accordance with the mass of air flow through said air intake passage, said means including a nozzle disposed in said air intake passage posteriorly of said throttle and proximate each cylinder of the engine, and engine temperature responsive means permitting manifold vacuum to act on said nozzle to increase the quantity of fuel flow therethrough in inverse proportion to engine temperature,

.said temperature responsive means being adapted to vent said nozzle to the intake passage anteriorly of the throttle valve to cause manifold vacuum to be ineffective to control when the engine reaches its normal operating temperature whereby said fuel supplying means solely determines the quantity of fuel flow through said nozzle.

References Cited in the file of this patent UNITED STATES PATENTS 2,223,381 Mock Dec. 3, 1940 

